A symbiotic nutrient exchange within the cyanosphere microbiome of the biocrust cyanobacterium, Microcoleus vaginatus.

ABSTRACT: Microcoleus vaginatus plays a prominent role as both primary producer and pioneer in biocrust communities from dryland soils. And yet, it cannot fix dinitrogen, essential in often nitrogen-limited drylands. But a diazotroph-rich "cyanosphere" has been described in M. vaginatus, hinting that there exists a C for N exchange between the photoautotroph and heterotrophic diazotrophs. We provide evidence for this by establishing such a symbiosis in culture and by showing that it is selective and dependent on nitrogen availability. In natural populations, provision of nitrogen resulted in loss of diazotrophs from the cyanosphere of M. vaginatus compared to controls, but provision of phosphorus did not. Co-culturing of pedigreed cyanosphere diazotroph isolates with axenic M. vaginatus resulted in

SUBMITTER: Nelson C 

PROVIDER: S-EPMC7853076 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature